No. 605] 



NOTES AND 



317 



ancestral to the Anura, and the Jurassic Anura are so entirely 

 modernized that they do not bridge over the wide structural gap 

 between the Paleozoic Amphibia and the modern frogs and toads. 

 It seems to the reviewer, after repeated comparisons of the 

 osteology of the Anura with that of many of the temnospondyls, 

 that some members of the latter group, in the brain-case, the 

 dermo-cranium and even in the vertebrae and limbs retain many 

 characters which may reasonably be looked for in Paleozoic an- 

 cestors of the frogs and toads ; and that such forms as Brachyops, 

 Cacops and Dissorophus, although not directly ancestral, differ 

 from the Anura chiefly in the retention of many primitive am- 

 phibian characters. It may be that some of the short-headed 

 Triassic temnospondyls of South Africa will furnish the linking 

 forms ; but at any rate it is interesting to note that the existing 

 frogs and toads retain a long series of characters in the skull 

 and skeleton which are seen in the Paleozoic temnospondyls, and 

 'that they differ from the latter in such modernized characters as 

 the following: the wide fenestration of the occiput and palate, 

 the resulting slenderness of the skull bones, the loss of the dermo- 

 supraoccipitals. tabnlars. ectopterygoids, pre- and post-frontals, 

 the completion of the auditory ring, the development of extreme 

 saltatorial adaptations in the skeleton, including the modifica- 

 tion of the vertebra? from the rhachitomous into the notocentrous 

 and epichordal types, the development of a long continuous uro- 

 style coincident with the forward shifting of the sacrum and 

 lengthening of the ilium. 



Dr. Hoodie's arrangement and sequence of the families of 

 mierosaurs appear to the reviewer to be highly confusing. It 

 would perhaps have been better, after beginning with the newt- 

 like types, to pass at once to the long-bodied Urocordylida? and 

 the snake-like Molgophiidtp and Ptyoniida\ instead of interjecting 

 in the middle of the series tlio Stegopida\ which appear to the 

 reviewer to be more nearly allied with the Temiiospondyli, and 

 the Amphibamidaa, which are heavy-liiuhed offshoots of the prim- 



The author's ordinal and family drfinitions aro oxtnMnely 

 full, but the reader will find so many diaractots that ai'c .-om- 

 mon to several families and sometimes orders, that it is difficult 

 to cull out the most striking ones. This the reviewer has at- 

 tempted to do in the subjoined table in which he has also included 

 the principal European families of branchiosaurs and miero- 

 saurs. The families of mierosaurs are arranged so far as pos- 



